1. Field
This disclosure relates to a method and apparatus for geotagging of a photograph, and more particularly, to a method and apparatus for tagging a photograph taken with a digital camera without a global positioning system (GPS) function or with a general film camera and uploaded on a website, with GPS information and a direction in which an object is photographed, in which two reference images tagged with GPS information are searched for, relative positions and directions between the images and an input image are obtained through image processing, and GPS information and direction information on the input image are determined and tagged by using the GPS information on the reference images.
2. Description of the Related Art
Recently, with the development of Internet technology and digital devices, many people upload and share photographs taken by using cameras in Internet photo sharing sites or their blogs. In addition, as map information services have been actively provided in recent years, methods of uploading photos in association with maps have spread gradually.
At this point, as the Internet service companies allow users to input information associated with shooting position in addition to simple upload of the photos in the Internet, the companies try to extend a new service area. The process of inputting position information is called geotagging.
By applying the tag information having the position information, travel information such as photos taken in advance by other people at real positions on a map can be obtained. As such, various types of information can be acquired. In addition, as leading Internet service companies provide photo services associated with positions, the interest in geotagging has increased.
In addition, a method of utilizing global positioning system (GPS) data for geotagging has started to spread, but it is still in the initial stage. In most cases, photos taken by people are manually tagged one by one through a comparison with a map.
As digital cameras are widespread, general users easily take photographs and upload their photos on the Internet blogs and photo sharing sites. When the photos are uploaded on a web album, the photos are arranged in time order, and the information such as a type of camera is displayed. This can be achieved because exchangeable image file format (EXIF) tag information is automatically stored in a photo header file when a photograph is taken with the camera.
Recently, cameras cooperative with the GPS as the geotagging method have started to spread, and attempts to store position information in the EXIF tag have been made. The GPS camera will additionally use a magnetic field sensor such as a digital compass in order to provide accurate information on a position and a viewpoint, that is, a direction of the camera at the time of taking a photograph.
The applicability of the photograph tagged with the position information including the direction information is great. There are advantages in that travel information can be directly checked on a map, and 3-dimensional (3D) reconstruction of an object from the acquired photos can be achieved with the position information on the camera. In order to apply these advantages, this kind of service has been competitively proposed to the Internet service companies.
However, as described above, since the cameras cooperative with the GPS are not common yet, it is not easy to provide the position and direction information to the existing photographs. Accordingly, a technique of tagging the existing photograph that does not include GPS information with position and direction information through image processing is required.